1. Field of the Invention
This inventions pertains generally to adhesive bonding and miscellaneous chemical manufacture, and more particularly to a surface bonding and assembly machine that wraps an indefinite running length flexible web onto a part. In one particular manifestation, the invention is an automated edge band applicator that precisely wraps both linear and non-linear work pieces. The machine severs the edge band from a spool to exactly wrap a part, independent of part-to-part variances.
2. Description of the Related Art
In the fabrication of various tables, shelving, other furniture, and a wide variety of other diverse objects, laminated material is often used, where major surfaces are often comprised of a thin lamina having a desired finish, decorative appearance, resistance to soiling, or the like. These major surfaces often conceal the underlying substrate, which might for exemplary purpose comprise a Medium Density Fiberboard (MDF) or other wood product or wood substitute. In such case, and without further finishing, the edges will betray the otherwise concealed MDF. Furthermore, these edges will often also be less durable, and easily damaged. Likewise, some wood products are produced with cut edges that are unfinished, porous, irregular or the like.
To attain the desired finish, appearance, durability and the like, the edges may be covered with strips or bands of decorative and durable material. Often this edge band is formed through a plastic extrusion process, and the band after extrusion and cooling is wrapped about or into a spool. This edge band will most preferably be wrapped to precisely encompass the edge of the object, neither overlapping nor leaving an unconcealed gap. Overlap will create an unsightly protrusion that is also more likely to be separated from the object. A gap is also unsightly, and while less likely to be separated, still presents a distinct edge that might accidentally be snagged, undesirably placing great force and stress on the adhesion between the edge band and underlying substrate. Heretofore, the precision required to neither overlap nor leave a gap has not been attainable with affordable automated machinery. Particularly troublesome are non-linear edges such as are found on oval table tops and other artistic and decorative shapes, since typical manufacturing tolerance variations will lead to shorter or longer distances along the non-linear edge. This means that simply measuring a predetermined length of banding material will not ensure precise lapping of the ends of the edge banding. Instead, and particularly with non-rectilinear work pieces, substantial manual labor has been required in the prior art to severe and secure the edge band.
Another challenge to automated banding has been associated with the edge band material. Depending upon the product, edge banding may be of diverse and sometimes inconsistent dimension. For exemplary purposes, some banding is quite thick, measuring 3 millimeters in thickness, while other banding is only one-half millimeter thick. As noted, there will also be tolerance based variation in these thicknesses, as well. The work piece thickness, which may dictate the width of the edge banding, might for exemplary purposes range from 10 to 60 millimeters. The design of an automated edge banding machine capable of handling the wide range of dimensions of edge banding used in the industry has been a stumbling point for much of the prior art.
A number of US patents, the teachings and content which are incorporated herein by reference, are exemplary of the existing edge banding machines and processes: U.S. Pat. No. 2,748,046 by Works et al, entitled “Method of edge-surfacing woody products”; U.S. Pat. No. 3,468,741 by Miller et al, entitled “Apparatus for applying edging tape to the edge of a workpiece”; U.S. Pat. No. 3,626,806 by Fritz, entitled “Protective and decorative edging”; U.S. Pat. No. 3,655,479 by Helmes et al, entitled “Method for gluing a strip of material against the side of a flat work piece, like a table leaf, and a device for peforming this method”; U.S. Pat. No. 3,753,832 by Veneziale, entitled “Edge banding machine”; U.S. Pat. No. 4,067,762 by Rhoads, entitled “Portable edge bander”; U.S. Pat. No. 4,222,812 by Duewel, entitled “Hot air edge banding machine”; U.S. Pat. No. 5,312,504 by Jorde, entitled “Edge veneering”; U.S. Pat. No. 5,693,174 by Nakata et al, entitled “Apparatus for attaching a molding”; U.S. Pat. No. 6,098,688 by Darovic, entitled “Device for improving an edgebanding machine”; U.S. Pat. No. 6,263,938 by Maioli et al, entitled “Panel edge banding device”; U.S. Pat. No. 7,189,442 by Jesse et al, entitled “Edge band and edge banding process”; U.S. Pat. No. 7,582,179 by Jesse et al, entitled “Edge band and edge banding process”; U.S. Pat. No. 8,430,144 by Lin, entitled “Edge banding machine”; and U.S. Pat. No. 8,443,858 by Lin, entitled “Edge banding machine”.
Other US patents, the teachings and content which are incorporated herein by reference, are exemplary of prior art edge bands: U.S. Pat. No. 2,705,820 by Torrence, entitled “Molding strip”; U.S. Pat. No. 3,590,754 by Jakobsen, entitled “Edge bandings for articles of furniture”; U.S. Pat. No. 4,503,780 by Apissomian, entitled “Table with resilient edge”; U.S. Pat. No. 4,558,553 by Kolk, entitled “Furniture article with edge molding”; U.S. Pat. No. 5,440,857 by Shanok et al, entitled “Endless edge trim fabricated from an extruded profile”; and U.S. Pat. No. 5,525,384 by Gilmore et al, entitled “Flexible molding strip having inserted decorative cord and furniture provided with such strips”.
In addition to the foregoing patents, Webster's New Universal Unabridged Dictionary, Second Edition copyright 1983, is incorporated herein by reference in entirety for the definitions of words and terms used herein.